Azo dyes



UNITED STATES PATENT OFFICE BERNHABD SCHGNER D'OT'I'O SmIBERT, 0F DESSAU, ANHALT, GERMANY, ASSIGNOBS TU ACTIEN GESELLSCHAFT E'U'R ANILIN FABRIKATION, OF BERLIN, GERMANY.

AZO DYES.

1T0 Drawing.

To all whom it may concern:

Be it known that we, BERNHARD ScHiiNER and O'rro SIEBERT, citizens of the German Republic, residing at Dessau, in Anhalt, German have invented certain new and useful mprovements in Azo D es, (for which I have, made a plication in erman May 7, 1914; in Eng and, April 6, L915; 111 Austria, March 8, 1915; a in Switzerland, March 26,, 1915, in France, Feb. 7' 1920, and in Czecho-Slovakia, Feb. 16, 19205 of which the following is a specification.

The objects of our present invention are new azo dyes as free acids corresponding to the general formula:

fonic acid, by reducing the nitro group and v by substitution of the resulting amino group in the desired manner. The new dyes form in the d state dark powders soluble in water with bluishred color, less soluble in alcohol, unsoluble in ether and benzene. By reducing a cute they are destroyed. They dye on woo bluish red tints of a very good fastness to the action of light and to washin and equalize in an excellent manner.

The following examples may serve to illustrate our invention without limiting it, the parts being by weight: y

1. 26 parts of the fi acetylamino-3-aminolunethoxy-benzene-4-sulfonic acid are diazotized in the usual nianner an united with 24 parts of 2-amino-8-na ht ol-6-sulfonic acid which may be dissolve in an alkali and separated by additiouof an acid in form of a ne precipitate. In order to finish the re action sodium acetate is added. The result ing dye is salted out, filtered and dried. It forms in dry state a dark powder, soluble in Specification of Letters Patent.

Patented Feb. 28, 1922.

water with reddish blue color, less soluble in alcohol,-unsoluble in ether and benzene. By reducing agents it is destroyed. It dyes on wool blueish red tents of an excellent fa'stness to the action of light.

2. The dye which may be obtained by couphng of the diazo compound of 21.8 parts of 4-nitro-aniline sulfonic acid with 2/! parts of 2-amino-8-naphthol-6-sulfonic acid and by reducing the nitro group is mixed with 400 parts of water and 250 parts of methyl alcohol. 12 parts of sodium carbonate and 20 parts of methyliodide are added; the mixture may be heated for 3 hours in an autoclave to-95100 G. Then the methyl alcohol and the excess of methyliodide are eliminated by distillation and the dye is separated by common salt. It forms in the dry shape a dark powder, soluble in water with bluish red color, less soluble in alcohol, insoluble in other and benzene. By strong reducing agents it is destroyed. It dyes wool beautiiul blueish red tints of a very good fastness.

3. The sodium salt of the dye 4-aminoa-niline-2-sulfonic acid-uzo (1) 2-amino-8-naphthol-fi-sulfonic acid (compare example 2) is treated in aqueous solution with the corres onding quantity of acetic anhydride. The

ye is separated by addition of common salt.

It forms in dry state a dark powder, soluble 8 in water with blueish red color, less soluble in alcohol, unsoluble in ether and benzene. By strong reducing agents it is destroyed. It dyes Wool in blueish red tints of very good fastness. a

4. The solution of 50 parts of the sodium salt of the dye 3-aminoaniline-2-sulfonic acid ezo- (1) 2-amino-S-naphthol-G-sulfonic acid in 250 parts of water is heated to 75 C.

and stirred with 60 parts of benzoyl chloride. In the course of an hour 10 parts of calcium carbonate are added. The mixture is stirred for an hour, the temperature being kept at 75 C. The dye is separated with common salt. In the dry state it forms a dark powder, soluble in water with blueish red color, less soluble in alcohol, unsoluble in ether and benzene. It. is destroyed by strong reducing agents and dyes on wool blueish red tints of a very good fastness.

It is obvious to those skilled in the art that our invention is not limited to the foregoing examples or to the details given therein. Dyes of the same qualities are obtained by substituting the amino group by other suhstituents for instance by the benzyl-group or its derivatives.

Having now described our invention and the manner in which it may be performed what we claim is,

1. The herein described new azo dyes, the general formula of the free acids being:

sour R meaning a substituent, such as hydrogen, alkyl-, ara kyl-acidyl-group, X meaning an univalent substituent-bemg iii the dry state dark powders, soluble in water to blueish red solutions from which wool is dyed blueish red, less soluble in alcohol, unsoluble in ether and, benzene, being destroy- -ed by reducing agents, yielding upon reduction 1.2-diamino-8-oxynaphthalene-6' sulfonic acid and a para-phenylene sulfonic acid derivative.

3. The herein-described new azo dyes, the general formula of the free acid being:

NH! I X meaning an univalent silbstituentfibcing in the dry state dark powders soluble in water to blueish red solutions. from which wool is dyed blueish rcd, less soluble in alcohol. llllhflllllile in ether and benzene, being destroyed by reducing agents yielding upon reduction l.Q-dinmlno-R-oxyna ihth:1 lene-(lsulfonir acid a mononridylutml paraphcnylencdiamiue sulfonic acid Icrivat rc.

4. The herein-described new azo dyes, the

general formula of the free acid being:

som

BOlH X meaning an uniyalent substituent -being in the dry state dark powders soluble in water to blueish red solutions, from which wool is dyed blueish red, less soluble in alcohol, unsoluble in ether and benzene being destroyed by reducing agents yielding upon reduction 1.2-diamino-8-oxynaphthalene-6- sulfonic acid and a monoacetylphenylenediamine sulfonic acid derivative.

5. The herein-described new azo dyes, the general'formula of thefree acid being:

O.Alkyl NH,

being in the dry state dark powders soluble in water to blueish red solutions from which wool is dyed blueish red, less soluble in alcohol, unsoluble in' ether and benzene being destro ed by reducing agents, yielding upon re uction 1.2-diamino-8-oxynaphthalene-6-sulfonic acid and a 1-amino-4- monoacetylarnino-5-alkyloxybenzene sulfonic acid (2).

6. The herein-described new azo dye, the general formula of the free acid being:

being in the dry state a dark powder soluable in water to ablueish red solution from which wool is dyed blueish red, less soluble in alcohol, unsoluble in ether and benzene, being destroyed by reducing agents yielding upon reduction 1.2-diamino-8-oxynaphthalene-G-sulfonic acid and l-amino-4-mononcetylamino 5 -methoxy benzene 2 -sulfarric acid.

In testimony whereof we affix our signatun-s in presence of two witnesses.

BERNHARD SCHONER. OTFO SIEBERT.

\Vitnesscs Lao Kitnimrms l AIlL SAM an. 

